Hemp is related to marijuana but has much lower levels of THC, the compound that provides the high to pot users. CBD is a non-psychoactive compound found in hemp, the Associated Press reported.

Like marijuana, hemp is already legal in some states. The bill that received final approval in Congress on Wednesday would make it legal nationwide. It's expected that President Trump will sign the bill into law next week.

Legalization could triple hemp sales in the United States to $2.5 billion by 2022, including $1.3 billion from hemp-sourced CBD products, according to cannabis market research firm New Frontier Data, the AP reported.

Proponents of CBD say it has many health benefits, ranging from pain relief to reducing anxiety, but experts point out that there is a lack of research on how CBD affects humans.

Under the new bill, the U.S. Food and Drug Administration retains its authority over products with CBD and it's unclear how the agency will react to hemp legalization, the AP reported.

In the past, the agency has sent warning letters to some companies selling CBD, and FDA Commissioner Scott Gottlieb has stated that CBD products will be treated like any other products that make unproven health claims.